SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47e9c6fe1ae4d1b86f7fdb636bac9eae8b67229257d365b184208dd77429262e' 
  AND token = 'dnhZ8LNaiPCyDyDp7JNxGmlfOoGA+oHUfsTmgcWwl7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}